1. Field of the Invention
The present invention relates generally to a super-wide angle lens, particularly to a super-wide angle lens having a field angle of 140.degree. or larger, and more particularly to a so-called fisheye lens having a large barrel-shape distortion.
2. Related Background Art
A fisheye lens is used widely as a photographing lens because of exhibiting a peculiar delineation owing to a wide field angle and a large distortion. Further, the fisheye lens is broadly employed as a monitoring lens and a lens for a scientific research by utilizing the wide field angle thereof.
This type of known conventional fisheye lens is disclosed in, e.g., Japanese Patent Publication No. 49-20534.
The prior art fisheye lens disclosed in the above Publication includes, however, eight or more pieces of lens elements. As a result, the conventional super-wide angle lens has such disadvantages that the configuration thereof is comparatively complicated, and the lens is expensive.